Integrated gear assembly

Abstract

An integrated gear assembly includes a conjoined carrier assembly coupling a reducing gear set to a differential gear set. This includes first, second and third coaxial sun gears. The first sun gear meshingly engages first gear elements of stepped pinion gears of the reducing gear set. The second sun gear meshingly engages third pinion gears of the differential gear set. The third sun gear meshingly engages fourth pinion gears of the differential gear set. The third pinion gears of the differential gear set axially overlap second gear elements of the stepped pinion gears of the reducing gear set. The fourth pinion gears of the differential gear set axially overlap the third pinion gears of the differential gear set.

The invention claimed is: 
     
       1. An integrated gear assembly, comprising:
 a conjoined carrier assembly coupling a reducing gear set and a differential gear set, wherein the reducing gear set includes a first sun gear, wherein the differential gear set includes second and third sun gears, and wherein the first, second and third sun gears are coaxial; 
 the first sun gear meshingly engaging a plurality of first gear elements of a plurality of stepped pinion gears of the reducing gear set, 
 the second sun gear meshingly engaging a third plurality of pinion gears of the differential gear set; 
 the third sun gear meshingly engaging a fourth plurality of pinion gears of the differential gear set; 
 the third plurality of pinion gears of the differential gear set axially overlapping a plurality of second gear elements of the plurality of stepped pinion gears of the reducing gear set; and 
 the fourth plurality of pinion gears of the differential gear set axially overlapping the third plurality of pinion gears of the differential gear set. 
 
     
     
       2. The integrated gear assembly of  claim 1 , further comprising the third and fourth plurality of pinion gears having equivalent axes of rotation relative to an axis of rotation of the coaxially arranged second and third sun gears. 
     
     
       3. The integrated gear assembly of  claim 1 , wherein the conjoined carrier assembly comprises a first carrier element, a second carrier element and a plate element. 
     
     
       4. The integrated gear assembly of  claim 3 , wherein the first carrier element includes a plurality of steps alternating with a plurality of indents arranged around a circumference and including a plurality of first axle mounts for the fourth pinion gears, a plurality of second axle mounts for the third pinion gears, and a plurality of third axle mounts for the second gear elements of the stepped pinion gears. 
     
     
       5. The integrated gear assembly of  claim 3 , wherein the second carrier element includes a plurality of steps alternating with a plurality of indents arranged around a circumference and including a plurality of fourth pinion axle mounts for the fourth pinion gears. 
     
     
       6. The integrated gear assembly of  claim 3 , wherein the plate element includes a plurality of axle mounts for the first gear elements of the stepped pinion gears. 
     
     
       7. The integrated gear assembly of  claim 1 , comprising the third pinion gears mounted to the conjoined carrier assembly each having a differential center distance less than a reducing center distance of the second gear elements of the stepped pinion gears. 
     
     
       8. An integrated torque-transfer gear set for transferring torque between a torque machine and first and second wheel assemblies, comprising:
 an integrated gear assembly rotatably mounted in a housing, said integrated gear assembly comprising: 
 a conjoined carrier assembly coupling a reducing gear set and a differential gear set, wherein the reducing gear set includes a first sun gear, wherein the differential gear set includes second and third sun gears, and wherein the first, second and third sun gears are coaxial, 
 the first sun gear meshingly engaging a plurality of first gear elements of a plurality of stepped pinion gears of the reducing gear set, 
 the second sun gear meshingly engaging a third plurality of pinion gears of the differential gear set, 
 the third sun gear meshingly engaging a fourth plurality of pinion gears of the differential gear set, 
 the third plurality of pinion gears of the differential gear set axially overlapping a plurality of second gear elements of the plurality of stepped pinion gears of the reducing gear set, and 
 the fourth plurality of pinion gears of the differential gear set axially overlapping the third plurality of pinion gears of the differential gear set; and 
 a stationary ring gear fixedly mounted in the housing concentric to the integrated gear assembly and meshingly engaging the first gear elements of the plurality of stepped pinion gears of the reducing gear set of the integrated gear assembly. 
 
     
     
       9. The integrated torque-transfer gear set of  claim 8 , comprising a single input member rotatably coupled between the torque machine and the first sun gear, and first and second output members rotatably coupled between the first and second wheel assemblies, respectively, and the second and third sun gears respectively, said single input member concentric to the first output member and coaxial to the first and second output members. 
     
     
       10. The integrated torque-transfer gear set of  claim 8 , further comprising the third and fourth plurality of pinion gears having equivalent axes of rotation relative to an axis of rotation of the coaxially arranged second and third sun gears. 
     
     
       11. The integrated torque-transfer gear set of  claim 8 , wherein the conjoined carrier assembly comprises a first coaxial carrier element, a second coaxial carrier element and a plate element. 
     
     
       12. The integrated torque-transfer gear set of  claim 11 , wherein the first coaxial carrier element includes a plurality of steps alternating with a plurality of indents arranged around a circumference and including a plurality of first axle mounts for the fourth pinion gears, a plurality of second axle mounts for the third pinion gears, and a plurality of third axle mounts for the second gear elements of the stepped pinion gears. 
     
     
       13. The integrated torque-transfer gear set of  claim 11 , wherein the second coaxial carrier element includes a plurality of steps alternating with a plurality of indents arranged around a circumference and including a plurality of pinion axle mounts for the fourth pinion gears. 
     
     
       14. The integrated torque-transfer gear set of  claim 11 , wherein the plate element includes a plurality of axle mounts for the first gear elements of the stepped pinion gears. 
     
     
       15. The integrated torque-transfer gear set of  claim 8 , comprising the third pinion gears mounted to the conjoined carrier assembly each having a differential center distance less than a reducing center distance of the second gear elements of the stepped pinion gears.